The term “proppant” is indicative of particulate material which is injected into fractures in subterranean formations surrounding oil wells, gas wells, water wells, and other similar bore holes to provide support to hold (prop) these fractures open and allow gas or liquid to flow through the fracture to the bore hole or from the formation. Uncoated and/or coated particles are often used as proppants to keep open fractures imposed by hydraulic fracturing upon a subterranean formation, for example, an oil or gas bearing strata, and provide a conductive channel in the formation.
Fracturing of the subterranean formation is conducted to increase oil and/or gas production. Fracturing is caused by the injection of a fluid (either a hydrocarbon, water, foam or emulsion) into a formation at a rate that exceeds the formation's ability to accept the flow. The inability for the formation to dissipate the fluid results in a buildup of pressure. When this pressure buildup exceeds the strength of the formation rock, a fracture is initiated. Continued pumping of the fracturing fluid will result in the fracture growing in length, width and height. The rate required to initiate and extend the fracture is related to the injection rate and viscosity of the fracturing fluid.
The fracturing process also includes placing a particulate material, referred to as a “proppant material”, “propping agent” or “proppant” in the formation to maintain the fracture in a propped condition when the injection pressure is released by resisting forces tending to close the fracture. As the fracture forms, the proppants are carried into the fracture by suspending them in a fracturing fluid or additional fluid or foam to fill the fracture with a slurry of proppant. Upon ceasing the injection of fluid, the proppants form a pack that serves to hold open the fractures. The propped fracture thus provides a highly conductive channel for the production of hydrocarbon and/or recovery of fracturing process water from the formation.
However, it has been observed that fluids flowing through the propped fracture have less than desirable or less than predicted flow rates. One theory is that the proppants forming the propped fracture are detrimentally affecting flow rates through the propped fractures.
It has been observed that during production from subterranean hydrocarbon bearing formations, formation wettability is an important parameter which affects fluid flow through the reservoir. Wettability is the tendency of one fluid to preferentially adhere to a solid surface in the presence of another immiscible fluid. While several strategies have been utilized to alter the wettability of the reservoir formation, current processes have not produced the desired wettability characteristics.
Accordingly, there is a need for a proppant material which is useful in improving fluid flow rates through propped features or reducing the effect of proppant materials on flow rates in a wellbore.